Round nestable paper container having a high gloss exterior finish and an interior and bottom wax coated surface



June 1969 R. E. LUDDER ROUND NESTABLE PAPER CONTAINER HAVING A H GLOSSEXTERIOR FINISH AND AN INTERIOR AND BOTTOM WAX TED SURFACE Filed Oct.25, 1967 v Sheet of 2 RODNEY E.LUDDER dd. ATTORNEY 3,450,327 GLOSSEXTERIOR TED CE 7 Z of 2 E. UDDER C A R HAVING A HIGH ERIOR AND BOTTOMWAX COA SURFA Sheet June 17, 1969 ROUND NESTABLE PAPER FINISH AND AN INTFiled Oct. 25. 1967 :7; w ll INVENTOR. RODNEY E LUDDER United StatesPatent 3,450,327 ROUND NESTABLE PAPER CONTAINER HAVING A HIGH GLOSSEXTERIOR FINISH AND AN IN- TERIOR AND BOTTOM WAX COATED SURFACE RodneyE. Ludder, Glen Head, N.Y., assignor to Owens- Illinois, lnc., Toledo,Ohio, a corporation of Ohio Continuation-impart of application Ser. No.605,338, Dec. 28, 1966. This application Oct. 25, 1967, Ser. No. 677,906

Int. Cl. 865d 5/40, 25/14, 5/56, 5/62, 3/00 US. Cl. 229--3.1 6 ClaimsABSTRACT OF THE DISCLOSURE A paper container having its interior coatedwith wax, means for preventing said wax from penetrating to the exteriorsurface of the side wall of the container and the exterior side wall ofsaid container having a glossy scuffproof surface; means for preventingmoisture penetration from penetrating towards the interior of thecontainer through the bottom and lower end thereof; and method ofproducing same.

BACKGROUND OF THE INVENTION Field of the invention and description ofthe prior art This application is a continuation-in-part of my copending application Ser. No. 605,338 filed Dec. 28, 1966.

This invention relates to two-piece paperboard containers intendedespecially for the packaging of comestibles and more particularly forcottage cheese and other cultured dairy products, salads, butter,spreads and the like which require low gas and/or moisture barrierproperties. It has been found that in the packaging of foods of thisnature it is difficult to prevent the transmission of moisture vapor andthe transmission of oxygen gas, the passage of both of which must beprevented in order to protect the flavor and freshness of the food. Forexample, it has been found that paperboard containers heavily coatedwith a suitable wax are much more 1mpervious to the passage of moisturevapor and oxygen gas than are many plastic containers. In the productionof such heavily waxed paperboard containers, it is (llfil' cult toproduce a highly glazed or glossy outer surface on the side wall of thecontainer, which is especially desirable where the side wall bearsfanciful designs often comprising multi-colors.

In the conventional heavily waxed two-piece paperboard containers, aheavy coating of wax is applied to the exterior surface as well as tothe interior surface and a highly glossy exterior surface of the sidewall is unobtainable without ruining the wax properties. For example,while it is possible to obtain high gloss on overall waxed foodcontainers simply by cold quenching them while the wax is still liquid,this sets up surface stresses which crack under refrigeration and thecontainers fail rapidly offering no resistance to the food.

SUMMARY OF THE INVENTION According to the present invention, the sidewall or body, comprises at least two plies which may be effected by adouble wrap made of one sheet or a single Wrap comprising a plurality ofsheets. In either event, an intervening blocking layer of materialseparates the inner and outer ply. The blocking layer may be in the formof an adhesive or glue which is impervious to the penetration of the hotwax applied to the interior of the container, or in the form of ablocking material which serves the same purpose, or a combinationthereof. The purpose of such construction is to prevent the hot waxapplied to the interior of the container from penetrating to theexterior surface of the container, which exterior surface is desired tobe coated with a glossy finish, either by means of a high gloss wax orby means of a suitable coating of plastic material, in the manner wellknown in the art.

The blank from which the side wall is to be made may be printed with thedesired design and colors, as is customary in present practice of paperprinting and coating, and thus provide a clear, high gloss finish,preferably by means of a thermosetting resin.

After the side wall and bottom of the container are assembled in themanner well known in the art, the interior of the container is coated bya special formulation of paraffin wax, which wax is prevented frompassing to the highly glossy outer surface of the side wall but ispermitted to penetrate the entire bottom of the container.

To provide moisture resistance from exterior sources, such as whennestable containers are placed in stacked relation and the bottom of onecontainer is seated within the lid of a lower container which often actsas a depository for moisture, the bottom surface of the container iscoated by a special formulation of paraffin wax. Alternately, the waxcoating may be applied substantially to the ledge of the containerbottom surface.

These coatings give the container the dual advantages of (1) an innerbarrier to the transmission of moisture vapor and oxygen gas, thusprotecting the flavor and freshness of the food product; (2) a superioroutside finish which not only contributes additional holding qualitiesto the package but complements and greatly enhances the printeddecoration of the container; and (3) an exterior barrier to thetransmission of moisture through the bottom surface of the container,thus protecting both the bottom member and seal between the bottommember and the side wall.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings wherein likenumerals refer to similar parts throughout the various views:

'FIG. 1 is a perspective top view of the container;

FIG. 2 is a sectional view taken at 2-2 of FIG. 1;

FIG. 3 is a somewhat diagrammatic view showing a cross section of a sidewall of the container made from a single sheet comprising two plies;

FIG. 4 is a similar view showing a cross section of a side wall of thecontainer made from a double wrap of a one-ply sheet;

FIG. 4a is a plan view on a somewhat reduced scale of the precut blankfrom which the double-wrapped side wall of the cup of FIG. 4 is madeshowing a printed pattern and the blocking coating on said blank;

FIG. 4b is a greatly enlarged sectional view taken at 4b4b of FIG. 4showing the two-ply side wall fabricated from the blank illustrated inFIG. 4a and showing the relation of the interior =wax coating on theinner ply,

FIG. 6 is a similar view showing the drainingof the excess wax out ofthe mouth of the container;

FIG. 7 is a view similar to FIG. showing the second step of squirting orpouring wax into the container;

FIG. 8 is a greatly enlarged sectional view taken at 88 of FIG. 7showing the two-ply side wall and the relation of the interior waxcoating on the inner ply, the barrier between the two plies and theexterior glazed finish on the outer ply of the side wall; and

FIGS. 9, 10 and 11 inclusive, are longitudinal sectional views showingthe coating of various portions of the container bottom.

Referring to the drawings, and more particularly to FIGS. 1 and 2, itwill be seen that the container indicated in general as 9 comprises atapered side wall designated in general as 10 and a bottom memberdesignated in general as 11. The side wall 10 comprises an inner ply 12and an outer ply 13 and an intermediate barrier comprising a blockinglayer 14, which may be in the form of a blocking adhesive 14a (FIG. 4b),which is preferably polyvinyl alcohol or vinyl acetate, the preferencebeing in the order named; or which may be in the form of a blockingcoating 14b which (FIG. 4b) is preferably of a clay base, as forexample, polyvinyl acetate and/or styrene butadiene latex combined witha clay material or titanium dioxide to obtain a white pigmentation toprint upon. It is contemplated that other suitable adhesives may beemployed, such as polyethylene or a starch adhesive, as well as avariety of suitable coatings, formulated to effect the desired barrierfor preventing the passage of hot wax through the outer ply 13.

As seen in FIG. 5, the container is formed in the manner well known inthe art having a bottom member 11, with an interior surface 110 and anexterior surface 11b, which is secured in position as by providing adownwardly peripherally extending flange 110 which is disposed betweenthe outer wall portion 100 adjacent the lower end of the side wall 10and the inwardly and upwardly turned end or skirt 10d of said end toform a pedestal 18. The bottom flange 11c is peripherally sealed betweenthe adjacent portions 100 and 10d of the side wall member 10 to providea liquid-tight seal. At the lower end of the pedestal 18, intermediateand integrally formed with said outer wall portion 10c and said upwardlyturned skirt 10d is a bottom ledge 102 on which the container 9 isgenerally supported. The complete bottom surface 11 as illustrated inFIG. 5, of the container 9, includes the bottom ledge 10e, skirt 10d andthe exterior surface 11b, which is the portion of the bottom member 11circumscribed by peripheral skirt 110. A suitable rolled rim or lip 15is formed on the open end of the container as is customary and in amanner well known in the art.

In FIG. 3 there is shown the conventional formation of a side wall by asingle wrap designated 10a which comprises at lease two plies ofmaterial adhered together by blocking adhesive with the ends of a singlewrap multiply sheet secured together in a side seam 16; while in FIG. 4there is shown the conventional manner of forming a side wall by two ormore wraps of a single ply sheet wherein the plies are laminatedtogether by means of an intervening adhesive, which may be a blockinglayer, and the ends of the single ply sheet are secured together as byside seam 17, as is customary in the prior art. As above indicated, theouter surface of the side wall 10 commensurate with the outer surface ofthe container may be printed on the container blank before the side wallof the container is formed and, whether plain or with a design, itsexterior surface may be provided with the desired high gloss.Preferably, the high gloss finish is provided by first printing and thencoating with a thermosetting resin to provide a clear, high glossprotective finish, such as 13'.

In FIG. 4a, there is shown a plan view of the present blank by which theside wall member 10]) is formed in accordance with a preferredembodiment of the invention. The blank side wall is of a length to formthe doublewrap container illustrated in FIG. 4 in which one-half of theblank, when formed, is the inner ply 12 and the other half the outer ply13. The paperboard stock carries a coating as, for example, a polyvinylacetate along with a binder which is preferably of a clay base material,and which may form the blocking coating as hereinafter discussed.

Preferably, the high gloss finish is provided by first printing uponone-half of one side of the wall 10b and then coating with athermosetting resin to provide a clear, high gloss protective finish as13. When the wall 10b is of this double-wrap construction, the blockingadhesive 14a is applied opposite the printed side of the blank. Whenwrapped this surface 14a contacts 14b. The blocking coating 14b iscontained on the inner ply 12 so that, in assembled relation for adouble-wrap container, we have illustrated in FIG. 4b an exterior highgloss coating 13', blocking coating 14b, outer ply 13, blocking layer14, formed of either or both the blocking coating 14b and blockingadhesive 14a, inner ply 12 with an interior wax coating 12 hereinafterdiscussed in detail. Thus as illustrated in FIG. 4b, we have a containerconstructed in which the blocking layer 14 intermediate the inner ply 12and outer ply 13 is comprised of both a blocking adhesive 14a and ablocking coating 14b. Depending upon the properties of the blockingadhesive 14a and the blocking coating 14b, either one or the combination of the two may constitute the blocking layer 14 and prevent thepenetration of the wax 12' from reaching the outer ply 13. An additionalfeature is that a secondary blocking layer 14 may be provided betweenthe ouer ply 13 and the high gloss protective finish 13 in the form ofblocking coating 14b to further assure the obt-ainment of a containerfree from unsightly wax marring on the exterior surface thereof and as abase for printing upon the container side wall 10.

After the side wall and bottom have been assembled to complete thepaperboard container 9 for either a singlewrap or double-warp container,the container is suitably held in a holder designated 20 and a series ofcontainers so held is carried on a conveyor with the longitudinal axesdisposed in the horizontal plane. The containers are rotated about theirlongitudinal axes while moved forward by he conveyor and wax is squirtedor poured into the interior of the containers as by nozzles 21. It willbe noted that the container 9 shown in the drawings has a tapered sidewall 10, which as is customary in the art, makes an angle of 4-7 to thecentral axis normally held in a horizontal plane. This slight angle issufficient to cooperate with the rotation of the container to evenlyspread the liquid wax applied through nozzle 21. However, to remove theexcess wax the container is tipped as shown in FIG. 6 to substantiallyincrease the side wall tilt and drain out excess wax 22. Of course, ifit is desired to treat cylindrical containers, the holder 20 is held onthe conveyor so that the container side wall is initially inclined at asuitable angle, say about 38, and thereafter tilted to a greaterinclination to drain out excess wax 22. The increased tilt angle asshown in FIG. 6 may be effected at one or more points in the path oftravel of the container, as by means of cam segments (not shown) as iswell known in the art.

The wax employed is preferably a compostion comprising 99.5% of fullyrefined paraffin wax having a melting point of 132-l34 F. and /a% of apolyethylene additive, such as one made by Eastman Chemical Companyknown in the trade as C13. This formulation of wax is applied in twosteps, the first at about 255 F. and after the excess has been drainedfrom the container as shown in FFIG. 6, a second application is madewith the above composition at about 180 R, such as by means of a nozzle23. After the second application the excess wax is drained from thecontainer and the container is dried.

As will best be seen in FIG. 8, the wax not only coats the interiorsurface of inner ply 12 to provide the interior wax caoting 12, butpartially penetrates the same to inhibit flaking. While this wax coatingthus applied is prevented from passing through the paper-adhesivelaminate to the exterior surface of the side wall 10, it does penetrateentirely through the bottom 11 of the container and a completepenetration through the bottom of the container is desirable so that thebottom is fully covered and the extra wax on the bottom adds strength tothe corner and center portions of the container and also further assuresa sealing fillet between the bottom member 11, and side wall 10.

For those containers stored or filled in a moisture laden or wetenvironment, it has been found desirable to provide a protective coatingof wax on the complete bottom surface of the container, or partsthereof, in a manner to prevent the moisture from saturating the sealbetween the outer wall portion 100, upwardly turned skirt d of the wall10 and the downwardly extending flange 11c therebetween. In practice,the filled containers are often stored in refrigerators and the bottomledge 102 of the pedestal rests within the lid of a lower stackedcontainer. The lid often contains a degree of condensation, such aswater, that upon storage for several days tends to saturate the ledge10e, upwardly turned skirt 10d and downwardly extending flange 11c toefiect a separation of the adhesive at the juncture therebetween whichaffects the structural rigidity of the container. When the skirt 10abecomes saturated. it starts to return to its original flat shapethereby applying a force on the overlapped seal which has a tendency tocrack the seal.

Referring more particularly to FIGS. 9, 10 and 11, we have illustratedan exterior was coating on the bottom surface, which wax may be of thesame type 12 as used to interiorly coat the container, and which wax isapplied either subsequent to the application of the interior wax asdecribed above or thereafter.

In FIG. 9, the bottom surface 11 is wax coated while the container ismounted generally vertically on a holder designated 25 and, which may berotated, while the wax is applied as by squirting to pouring it on tothe ledge 10e thereof by nozzle 26. Preferably when the entire bottomsurface is to be coated the container and supply of melted wax aremaintained in horizontally spaced relationship and moved along a definedpath relative to each other to coat the surface thereof. Controllingmeans 27 is provided, which may be in the form of an outer guard meansin the form of funnel 28 and an inner guard means in the form of funnel29, mounted for relative movement with respect to each other in anyconventional manner not shown, to confine the area of application of thewax and then move the container and control means relative to each otherfor waxing of the next container. The spacing at the mouth of thefunnels is substantially equal to the width of the ledge 10e to assurethat the wax substantially coats the ledge only and not the exteriorhigh glass finish.

FIG. 10 illustrates the invention wherein the bottom ledge 10c and skirt10d are coated with the wax particularly the junction between the latterand bottom member 11a, The nozzle 26 is positioned within the confiningmeans 27 formed by the outer funnel 27 and inner funnel 29 and thelatter terminating in spaced relation to the upwardly turned skirt 10dwhich is wax coated with the ledge 10e.

FIG. 11 illustrates the invention wherein the entire bottom surface 11including the skirt 10d, bottom ledge 10a and the exterior surface 11b,enclosed by the skirt 10d, are coated as by positioning the nozzle 26 inspaced relation to the bottom 11 and providing control means 27 in theform of the funnel 28 having a diameter at its base substantially equalto the outer diameter of the container. Alternately, the bottom member11 and skirt 10d may be wax coated by reducing the diameter of thecontrol means 27. The holder can be simultaneously rotated relative tothe nozzle 26, in any conventional manner to properly disperse the waxbeing applied or the holder and nozzle 26 may be maintained in fixedrelationship to each other. In addition the wax is applied through thenozzle 26 in timed relation to the positioning of the container inoverlapping relation thereto. The container may be intermitt'entlystopped when the wax is applied thereto.

Thus in accordance with the present invention applicant has invented apackaging container of the nestable type which for the first timecombines many ideal characteristics not heretofore available in a singlecontainer. The invention permits the obtainment of a high exteriorglossy finish which has long been desired for beauty and texture toproperly attract the eye of the consumer, and still have the qualitiesthat permit the storage of the container for prolonged periods of time,due to its wax coated interior and bottom surface. The wax coated bottompermits the container to remain on a damp or moistened surface for aconsiderable period of time without affecting the structure of thecontainer and more importantly the contents contained therein.

Having thus described my invention with particularity with reference toits preferred form, it will be obvious to those skilled in the art,after understanding my invention, that other changes and modificationsmay be made therein without departing from the spirit and scope of myinvention, and I aim in the appended claims to cover such changes andmodifications as are within the scope of the invention.

What is claimed is:

1. A paper container, comprising (A) a tapered side wall member and abottom member secured thereto in sealing engagement therewith at one endthereof to form a bottom on which the container is supported, said sideWall extending upwardly and outwardly from said bottom member andterminating in an open top having a peripheral lip,

(B) said side wall member comprising an inner ply and an outer ply withan intervening blocking layer of material,

(C) an exterior high gloss finish on said outer ply with an interveningblocking layer of material,

(D) an interior wax coating on said inner ply, said blocking layersserving as barriers preventing said interior wax coating frompenetrating to and marring said exterior high gloss finish, and

(E) an exterior wax coating on said bottom, said exterior wax coatingserving as a barrier preventing moisture from penetrating and separatingthe seal between said side wall member and said bottom member wherebysaid container may be positioned on a wet surface for prolonged periodsof time without affecting the structural rigidity thereof.

2. A paper container as set forth in claim 1 wherein said blocking layerbetween said inner and outer plies comprises a blocking coating on saidinner ply, and a blocking adhesive between said blocking coating andsaid outer ply and securing said outer ply and said coated inner plytogether.

3. A paper container as set forth in claim 2 wherein said blockingadhesive is a starch adhesive, and said blocking coating is a clay basecoating.

4. A paper container as set forth in claim 1 wherein said blocking layerbetween said inner and outer plies is polyvinyl alcohol.

5. A paper container as set forth in claim 1 wherein said interior waxcoating is a composition comprising approximately 99.5% of a fullyrefined parafiin wax having a melting point of about 132134 F. and 0.5%of a polyethylene additive.

6. A paper container as set forth in claim 1 wherein said bottomincludes (a) a bottom ledge integrally formed with said side wall memberat the closed end of the container and on which the container issupported, and

(b) an upwardly extending skirt integrally formed with said bottomledge,

7 8 (c) the exterior surface of said bottom member being 2,774,69212/1956 Shelley et a1. 117-155 circumscribed by said skirt, 2,853,222 9/1958 Gallagher 2293.1 X and said exterior wax coating is disposed on andextends 2,999,765 9/1961 Boenau 2293.1 X continuously over said ledge,skirt, and bottom member 3,137,432 6/1964 Rein et a1. 2293.1 exteriorsurface. 5

References Cited DONALD F. NORTON, Primary Examiner.

UNITED STATES PATENTS C1. X'R 1,448,329 3/1923 Bohlman 2293.1 11795;229-1.5

2,399,338 4/1946 Ford.

